http://www.cps.gov.uk/legal/a_to_c/c...ions_offences/
Improper use of public electronic communications network - Communications Act 2003, section 127
The Communications Act 2003 section 127, see Stones 8.30110B, covers the sending of improper messages. Section 127(1)(a) relates to a message etc that is grossly offensive or of an indecent, obscene or menacing character and should be used for indecent phone calls and emails. Section 127(2) targets false messages and persistent misuse intended to cause annoyance, inconvenience or needless anxiety; it includes somebody who persistently makes silent phone calls (usually covered with only one information because the gravamen is one of persistently telephoning rendering separate charges for each call unnecessary).
If a message sent is grossly offensive, indecent, obscene, menacing or false it is irrelevant whether it was received. The offence is one of sending, so it is committed when the sending takes place. The test for "grossly offensive" was stated by the House of Lords in DPP v Collins [2006] 1 WLR 2223 to be whether the message would cause gross offence to those to whom it relates (in that case ethnic minorities), who need not be the recipients. The case also said that it is justifiable under ECHR Art 10(2) to prosecute somebody who has used the public telecommunications system to leave racist messages.
A person guilty of an offence under section 127 CA 2003 shall be liable, on summary conviction, to imprisonment for a term not exceeding six months or to a fine or to both. This offence is part of the fixed penalty scheme.
It is more appropriate to charge bomb hoaxes under section 51 of the Criminal Law Act 1977. See Chambers v DPP [2012] EWHC 2157 (Admin) , and Public Order Offences, elsewhere in the Legal Guidance.
Section 127 can be used as an alternative offence to such crimes for example as hate crime (including race, religion, disability, homophobic, sexual orientation, and transphobic crime), hacking offences, cyber bullying, cyber stalking, amongst others.